Method and apparatus for the production of a continuous tobacco rod



June 19, 1962 B. SCHUBERT METHOD AND APPARATUS FOR THE PRODUCTION OF A CONTINUOUS TOBACCO ROD 2 Sheets-Sheet 1 Filed May 11, 1960 5a 5b 2c 17b Ill Fig. 1a

June 19, 1962 B. SCHUBERT METHOD AND APPARATUS FOR THE PRODUCTION OF A CONTINUOUS TOBACCO ROD 2 Sheets-Sheet 2 Filed May 11, 1960 lhp ooooooooo s Fig. lb

HH HHW FigJc Patented June 19, 1962 ice 3,039,473 METHOD AND APPARATUS FOR THE PRODUC- TION OF A CGNTHNUOUS TOBACCO ROD Bernhard Schubert, Hambnrg-Lohbrugge, Germany, as-

signor to Hanni-Werke Korber & Co. K.G., Hamburg- Bergedorf, Germany Filed May 11, 1960, Ser. No. 28,310 Claims priority, application Germany June 12, 1959 7 Claims. (Cl. 13184) The invention relates to cigarette manufacture and is directed to an apparatus for producing a continuous tobacco rod for use in the production of cigarettes and the like, and more particularly to an apparatus involving the trimming and equalizing the upper surface of a tobacco stream while the same is supported by a suitable conveyor device.

For trimming and/or equalizing the normally uneven upper surface of a tobacco stream after it has been deposited upon a conveyor band by a tobacco distributor, it has been proposed heretofore in a copending application identified below of the assignee of this application to provide a trimming or equalizing device above the tobacco stream which device trims the upper surface of the tobacco stream, for example with a cutting action, and it has been suggested that the tobacco stream be held in a groove under the influence of suction acting transversely to its direction of movement while being moved to the trimming and/or equalizing point. The conveyor, for example a tobacco receiving and conveying belt, or, in accordance with a copending application of the applicant, a peripheral groove provided in a rotary conveyor wheel is made air permeable for this purpose and moves past a stationary suction chamber the suction effect of which remains uniform over the entire length of the suction chamber.

It has, however, been found that substantially better filled cigarettes can be produced when according to an important object of the invention provision is made so that the suction action is progressively reduced as the tobacco stream approaches the trimming point, and in fact in some cases may be reduced to zero by the time this point is reached.

This has the result that the suction action required for filling the tobacco into the groove and by the influence of which suction the tobacco fibres located on the upper surface of the tobacco stream are drawn into the conveyance plane, is progressively reduced in the path of the tobacco stream to the trimming point so that when moving past the withdrawal point the tobacco stream has the texture or fibre structure desirable for optimum trimming of the upper surface thereof so as to provide a uniform stream.

The progressive releasing of the tobacco fibres from the suction action may be obtained by means of a cover plate arranged between the suction chamber and the conveyor and having an opening the dimensions of which progressively are reduced towards the trimming point and preferably reach zero near or at this point. For this purpose the opening of the cover plate may have the shape of a single slot-like tapering aperture. The cover plate may also be perforated in the manner of a screen whereby the number and/ or size of the apertures decrease towards the trimming point. Instead of apertures, slots also can be provided which become narrower towards the trimming point, and provision can be also made so that the spacing of the slots decrease towards the trimming point.

According to another object of the invention the suction chamber consists of several partial chambers facing the tobacco stream, whereby each chamber is in communication with a common main chamber through ports conveniently made of adjustable cross-section and arranged in an intermediate wall. Such a wall with its ports thus acts in the same way as the aforesaid cover plate.

The objects of the invention are shown in the accompanying drawings which disclose two basic constructional examples:

FIG. 1 is a partial view in elevation with parts broken away and shown in section of a rotary suction conveyor wheel and a cooperating trimming device in which the suction chamber is covered in accordance with the present invention by a cover plate,

FIG. 1a is a developed plan view of a part of the cover plate used in the embodiment of FIG. 1,

FIGS. lb and 1c show other embodiments of the cover plate in partial development, and

FIG. 2 is a partial view similar to that shown in FIG. 1 of another embodiment of the invention.

In FIG. 1 there is shown as a constructional example a device serving for conveying and forming a tobacco stream. The device consists essentially of a rotary suction conveyor wheel 2 rotating about a horizontal axis 1 in a vertical plane, a suction chamber 4 fixedly connected to a stationary end cover 3 of the wheel 2, a connecting pipe 4a leading to a source of suction, not shown, and a rotary trimming or cutting device 502, 5b arranged at a predetermined point on the circumference of the wheel 2. The suction wheel 2 is provided with a groove 2a in its periphery and this groove has a bottom wall which has the form of a drum-like screen 2b. The annular groove 2a is in communication through this screen 2b with a series of radial chambers 20 extending in circumferential direction. Between the rotary suction conveyor wheel 2, and the stationary end cover 3 is arranged a drum-like stationary cover plate 6 having openings through which the radial chambers 20 are in communication with the stationary suction chamber 4.

The drum-like cover plate 6, which will be described in greater detail below, may be provided with two apertures 7 which are in communication with the atmosphere through ducts 8 extending through the end cover 3.

In the lower region of the rotary suction conveyor wheel 2 is located a tobacco conveyor belt 9 bearing against the periphery of the wheel 2. This conveyor belt carries on its upper horizontal stretch a tobacco stream 11 formed thereon by means of a well known tobacco distributor (not shown). The trimming device arranged at the upper peripheral region of the rotary suction conveyor wheel 2 may be constructed as described in the copending application Serial No. 3,877 filed January 21, 1960 by Richter and Ringe. This trimming device has two star wheels 5a in which the teeth of one wheel enter into the spaces between the teeth on the other star wheel while a circular cutter 5b rotates above the same.

The circular cover plate 6, a part of which is shown in development in FIG. la, is provided in the region of the suction chamber 4 with a slot-like aperture 1% progressively convergently tapering towards the cutting device 5a, 5b. When the direction of rotation of the suction conveyor wheel 2 as indicated by the arrow-x the cross sectional area of the slot in the cover plate 6 is progressively decreased from the beginning A to the end E of the suction chamber 4. As a result of the throttling action due to the reduction in the cross section the suction operating on the groove 2a in the suction conveyor wheel 2 progressively decreases over the region A to E being either reduced to a low value or even to a zero at the trimming device 5a, 5b. The progressive reduction in the cross-sectional fiow area of the coverplate 6 can also be secured by using several individual ports or openings, for example as shown in FIG. 1b, by a series of perforations 10' forming a screen with a progressively smaller number of perforations or smaller sized perforations as shown in FIG. 10 where parallel transverse slots 10" are used the width of which decreases toward the cutting device, while at the same time their mutual spacing 1s increased.

The device shown in FIG. 1 and FIGS. 1a, lb or 10 operates as follows:

A suitable distributor (not shown) showers cut tobacco onto the endless conveyor belt 9 moving in the direction of the arrow Y and forms a tobacco stream 11 on the top stretch of this belt. This tobacco stream 11 is conveyed into the groove 2a of the rotary suct1on conveyor wheel 2 in the region where the endless belt changes its direction and at the start A of the suction chamber 4. The tobacco stream in the annular groove 2a is subjected to a powerful suction which draws the tobacco into the groove 2a in such a manner that the latter 1S compactly filled with tobacco. The suction serves not only for drawing the tobacco into the groove, but also for safely retaining the tobacco therein during further movement by the conveyor wheel 2. The excess tobacco 11a projects outwardly of the groove 2a.

Corresponding to the progressive reduction in the passage section of the cover plate 6, the suction acting on the tobacco moving with the groove 2a progressively decreases over the length of the suction chamber 4 from A to B so that the initially compacted tobacco may be come progressively loose until finally it is largely or completely freed from any suction by the time the tobacco reaches the trimming device 5a, 5!). If a complete absence of suction is desired, the chamber 4 may terminate short of the trimming device 5a, 5b. Further, to ensure that the tobacco has assumed its natural loosened structure, the cover plate 6 may be provided with additional apertures 7 which provide a connection means from the groove 2a through the openings in the screen 2b, the radial chambers 20 and the ducts 8 to the atmosphere so that at the time the tobacco is trimmed it is no longer subjected to any suction whatever. The thus equalized tobacco stream 11b is conveyed in a known manner by the upper portion of the wheel to another horizontally moving conveyor device, not shown, which delivers the tobacco stream to a cigarette rod forming device.

This complete absence of the suction action by the time the trimming point 5a, 5b is reached need not be maintained in every case as it may be found desirable to merely reduce the suction to a low value by the time the trimming point is reached but without reducing the suction to zero. In an arrangement of this type the trimming device 5a, 5b is positioned adjacent to the end portion E of the suction chamber 4 where the aperture 10 in the cover plate 6 has only a very small dimension. In such a case a small amount of suction is maintained at the trimming point and this suction may be effective up to the point where the trimmed tobacco stream leaves the rotary suction conveyor wheel in a horizontal direction for passing onward into a cigarette rod forming device.

In the embodiment of the invention shown in FIG. 2 the tobacco stream 11' conveyed by the tobacco conveyor belt 9a is pressed into a groove formed between two upright and horizontally moving endless belts l3 and a horizontal endless suction belt 14, by means of an upper endless steel belt 12 and conveyed towards the trimming device 5a, 5b. The tobacco stream 11b trimmed by the cutting device 5a, 5b is transferred to the endless conveyor belt 9b. The suction chamber assembly 4' arranged beneath the upper horizontal stretch of the suction belt 14 consists of several partial chambers 15 each of which is in communication with a common main chamber 17 through ports 16. The ports 16 are progressively of reduced size in the direction of travel of the suction belt 14 so that the partial chamber 15 lying nearest the cutting device has the smallest port 16. The chamber 17 is connected to a suction pipe 18 and the partial chambers 15 and the openings 16 in the horizontal wall 16a perform the same function as the cover plate 6 in the embodiment shown in FIG. 1. Consequently the influences operating on the tobacco are similar to those already described so that they need not be further explained in detail. Furthermore, as shown in FIG. 2, the cross section of one or more of the ports 16 may be made adjustable by means of a threaded valve needle 19 to provide a very fine adjustment of the suction action within certain limits.

What I claim is:

1. In an apparatus for trimming and equalizing a continuously moving tobacco stream, a continuously moving conveyor provided with a tobacco stream receiving groove extending in the direction of movement of said conveyor, means for supplying said groove continuously with tobacco, a trimming device arranged at a predetermined position adjacent said conveyor and past which said tobacco stream is moved by said conveyor, said trimming device trimming an exposed portion of said tobacco stream to equalize the latter, said groove having a perforated bottom wall, a stationary suction chamber extending along a portion of said perforated bottom wall to subject the tobacco in said groove to suction, and means arranged between said perforated bottom wall and said suction chamber to progressively reduce the effect of suction along a predetermined length of said perforated bottom wall in advance of said trimming device.

2. In an apparatus according to claim 1, in which said means consists of a cover plate arranged between said perforated bottom wall and said suction chamber provided with a single lengthwise extending slot which progressively becomes narrower toward said trimming device.

3. In an apparatus for trimming and equalizing a continuously moving tobacco stream, a continuously moving conveyor provided with a tobacco stream receiving groove extending in the direction of movement of said conveyor, means for supplying said groove continuously with tobacco, a trimming device arranged at a predetermined position adjacent said conveyor and past which said tobacco stream is moved by said conveyor, said trimming device trimming an exposed portion of said tobacco stream to equalize the latter, said groove having a perforated bottom wall, a stationary suction chamber ex tending along a portion of said perforated bottom wall to subject the tobacco in said groove to suction, and means arranged between said perforated bottom wall and said suction chamber to progressively reduce the effect of suction along a predetermined length of said perforated bottom wall in advance of said trimming device, said means comprising a cover plate extending lengthwise of said conveyor groove over said suction chamber and provided with perforations the number per unit area decreasing progressively toward the trimming device.

4. In an apparatus for trimming and equalizing a continuously moving tobacco stream, a continuously moving conveyor provided with a tobacco stream receiving groove extending in the direction of movement of said conveyor, means for supplying said groove continuously with tobacco, a trimming device arranged at a predetermined position adjacent said conveyor and past which said tobacco stream is moved by said conveyor, said trimming device trimming an exposed portion of said tobacco stream to equalize the latter, said groove having a perforated bottom Wall, a stationary suction chamber extending along a portion of said perforated bottom wall to subject the tobacco in said groove to suction, and means arranged between said perforated bottom wall and said suction chamber to progressively reduce the effect of suction along a predetermined length of said perforated bottom wall in advance of said trimming device, said means comprising a cover plate extending lengthwise of said conveyor groove over said suction chamber and provided with a series of lengthwise spaced transverse slots the width of which decreases toward said trimming device.

5. In an apparatus for trimming and equalizing a continuously moving tobacco stream, a continuously moving conveyor provided with a tobacco stream receiving groove extending in the direction of movement of said conveyor, means for supplying said groove continuously with tobacco, a trimming device arranged at a predetermined position adjacent said conveyor and past which said tobacco stream is moved by said conveyor, said trimming device trimming an exposed portion of said tobacco stream to equalize the latter, said groove having a perforated bottom wall, a stationary suction chamber extending along a portion of said perforated bottom wall to subject the tobacco in said groove to suction, and means arranged between said perforated bottom wall and said suction chamber to progressively reduce the effect of suction along a predetermined length of said perforated bottom wall in advance of said trimming device, said means comprising a cover plate extending lengthwise of said conveyor groove over said suction chamber and provided with a series of lengthwise spaced'transverse slots the width of which decreases toward said trimming device while the distance between said slots increases toward said trimming device.

6. In an apparatus for trimming and equalizing a continuously moving tobacco stream, a continuously moving conveyor provided with a tobacco stream receiving groove extending in the direction of movement of said conveyor, means for supplying said groove continuously with tobacco, a trimming device arranged at a predetermined position adjacent said conveyor and past which said tobacco stream is moved by said conveyor, said trimming device trimming an exposed portion of said tobacco stream to equalize the latter, said groove having a perforated bottom wall, a stationary suction chamber extending along a portion of said perforated bottom wall to subject the tobacco in said groove to suction, and means arranged between said perforated bottom wall and said suction chamber to progressively reduce the effect of suction along a predetermined length of said perforated bottom wall in advance of said trimming device, said means comprising a wall extending lengthwise of said conveyor groove and spaced from the perforated bottom wall thereof, transverse walls between said wall and said perforated bottom wall to form a series of individual suction boxes, ports for connecting each said suction box with said suction chamber extending below said lengthwise extending Wall, said ports decreasing in size toward said trimming device.

7. In an apparatus for trimming and equalizing a continuously moving tobacco stream, a continuously moving conveyor provided with a tobacco stream receiving groove extending in the direction of movement of said conveyor, means for supplying said groove continuously with tobacco, a trimming device arranged at a predetermined position adjacent said conveyor and past which said tobacco stream is moved by said conveyor, said trimming device trimming an exposed portion of said tobacco stream to equalize the latter, said groove having a perforated bottom Wall, a stationary suction chamber extending along a portion of said perforated bottom wall to subject the tobacco in said groove to suction, means arranged between said perforated bottom wall and said suction chamber to progressively reduce the effect of suction along a predetermined length of said perforated bottom wall in advance of said trimming device, said means comprising a wall extending lengthwise of said conveyor groove and spaced from the perforated bottom wall thereof, transverse walls between said wall and said perforated bottom wall to form a series of individual suction boxes, ports for connecting each said suction box with said suction chamber extending below said lengthwise extending wall, said ports decreasing in size toward said trimming device, and manually adjustable valve means for adjusting at least the effective size of one of said ports.

References Cited in the file of this patent UNITED STATES PATENTS 1,869,395 Stelzer Aug. 2, 1932 2,617,426 Patterson Nov. 11, 1952 2,660,178 Rault Nov. 24, 1953 FOREIGN PATENTS 469,587 Germany Dec. 14, 1928 5,612 Great Britain 1894 764,551 Great Britain Dec. 28, 1956 

